326 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



branches of the median vein run out to the margin unforked; of the three 

 connecting veinlets between radius and radial sector the second is more than 

 twice as near the third than to the first; 8 costal cross-veins. 

 Length 8 mm. 



PROTOSIALIS BIMACULATA, sp. nov. 

 TYPE. M. C. Z. 10,842. Bolivia: Rio Longo (H. Fassl). 



Black, with yellowish head and prothorax. In general closely similar to 

 P. mexicana, but the head has a distinct black spot above each antenna, and 

 behind the eye is a black trifid mark back of the upper part of eye, instead of 

 the much larger bifid mark back of entire eye in P. mexicana. The wings are 

 infumate much as in P. americana, not as black as P. mexicana,' the venation 

 about as in P. mexicana, the basal cross-vein between the cubitus and first 

 anal ends on cross-vein much beyond origin of radial sector, the first cross- 

 vein between radius and radial sector is transverse instead of oblique as in 

 P. mexicana. 



Length to tip of wing 15 mm. 



SlALIS AEQUALIS, Sp. HOV. 



TYPE. M. C. Z. 10,843. Va.: Falls Church, 19 April to 25 June 

 (N. Banks). Mich.: Agricultural College (R. H. Pettit). Maine: 

 Norway (S. I. Smith). Mass.: Milford, 8 June. N. J.: Lafayette, 

 26 May. 



Deep black, some specimens showing the wings paler beyond the basal third. 

 Structure in general similar to S. infumata and S. concava but the ventral plate 

 of male is nearly as long as broad, with subparallel sides, and a broadly rounded 

 tip, usually covering all the other parts from below; the last dorsal segment of 

 male is broadly excavate below, not so deeply nor so narrowly as in the other 

 species. The hair of head and thorax is very short as in the other eastern 

 species; the middle veinlet connecting radius and radial sector oblique as in 

 other eastern species. 



Expanse 16-19 mm. 



SlALIS CALIFORNICA, Sp. HOV. 



Type. M. C. Z. 10,844. Calif.: San Emigdio Canon, Kern Co., 

 3 June (F. Grinnell); Summit, Sierra Nevada (Osten Sacken); San 

 Geronimo, 20 April (Osten Sacken); Saucelito, 15 May (H. Edwards). 



Deep black; with rather long dense hair on head and thorax, and with the 

 second connecting veinlet between radius and radial sector straight as in the 



